Improvement in hot-air furnaces



2 Sheetr-Shef 1.

JOHN H. BUR'TIS.

Improvement in Hot-Air Furnaces.

Patented June 6.1871- Nb. 115,699. E81

2 Sheets--Sheef 2.

JOHN H. B'U'RTlS.

improvement in Hot Air' Furnace.

Patented June 6,1871.

JOHN H. BURTIS, OF BROOKLYN, NEW YORK.

IMPROVEMENT m HOT-AlR FURNACES.

Specification forming part of Letters Patent No. 115,699,, dated J une6, 1871.

I, JOHN H. BURTIS, of Brooklyn, in the county of Kings and State of NewYork, have invented an Improved Hot-Air Furnace, of which the followingis a specification:

The object of my invention is to increase the extent of radiatingsurface and retain a compact and simple form, and to so construct theparts that they are connected by none but horizontal joints; and itconsists in an enlarged drum or cylinder surrounding thecombustion-chamber, with intervening air-pas sages on each side, saiddrum forming hori zontal fines for conveying the gaseous productsofcombustion in two equal volumes from the front to the rear; in theemployment of a dome-shaped top to the combustion-chamber, whichcommunicates with the smoke-pipe by the opening of a damper therein; andalso in a supplementary heating-chamber above the dome.

As represented in the drawing, Figure 1 is a sectional elevation; Fig.2, a horizontal section on the line m m, Fig. 1; and Fig. 3 is a rearelevation with the casing in section, showing the fiues J J, whichconvey the products from the fines I I to the base chamber L andsmoke-pipe 0. Fig. 4 is a vertical section of a portion of the drum andcombustion-chamber, showing one of the air-passages in its relation tothe adjacent parts.

The fire-pot A has underneath it an ashchamber, B, and is provided witha grate of any suitable form. Directly over the fire-pot is acombustion-chamber, O, of a larger diameter than that of the fire-pot,and surmounted by the concave dome D. In the front side of thecombustion-chamber is the passage E, which communicates with the door Fin the outer case G G, for the introduction of fuel. Thecombustion-chamber O is surrounded by a drum or cylinder, H H, whichcontains the horizontal flue-passages I I and the vertical air-passagesK K. The former carry the products of combustion in two equal columnsfrom the front to the rear part, as indicated by the arrows where theydescend the downward fines J J into the chamber L, situated in the rearportion of the base. From this chamber the smoke-pipe 0 starts(beginning near the bottom in order to force the heated products to thelowest point) and ascends outside of the dome H, inclining inward abovethe dome D, where it unites with the supplemental chamber M. With thetop of the latter the main smoke-pipe N is connected, which communicateswith the chimney. The dome ofthe combustion-chamber and the supplemental chamber M are separated by the damper P, which is kept closed, exceptin starting the fire, when it is opened to give a direct draft.

The flame and gases of combustion ascend and circulate around the dome Dbefore finding egress through the fines I I, thus heating a large areaof radiating surface directly exposed to the air contained within theheatingchamber or inclosing-case Gr G, the surface so heated comprisingnot only the exterior wall of the fire-pot, but the outer sides of thecombustion-chamber a and the interior surfaces a? of the fines I I,(between which the air circulates in the passages K K,) as well as theexterior surface of the entire drum H, downward fiues J J, chamber L,smoke-pipe O, and supplementary chamber By means of this large amount ofradiating surface efficient heating capacity is obtained with a moderatefire, by which the vitality of the air is not destroyed by subjecting itto too high a temperature. i

The parts are so constructed as to be fitted with horizontal jointsonly, the combustionchamber and its adjuncts having a single joint, 12b, and the bends 0r elbows of the pipes being cast entire, so thatabsolutely-tight fitting of that part is rendered an easy matter, anddeleterious gases are prevented from mingling with the air heated.

The furnace is equally well adapted for setting in brickwalls orsheet-metal casing. The cold air may be admitted underneath the bottomplate 13,, or in any other convenient manner.

Access to the ash-chamber is had by the I I, substantially as set forth.

2. In combination therewith, the downward flue-passages J J,supplementary chamber L, and smoke-pipe 0, arranged and operatingsubstantially as set forth.

JOHN H. BURTIS. Witnesses:

KATE N. J oNEs, WHEELER W. PHILLIPS.

